1. Field of the Invention
This invention relates to a conveying system wherein a plurality of drive means spaced by a predetermined distance are arranged along a path of conveyance for running a carriage by the forward propelling force and reverse propelling force imparted by the plurality of the drive means, and more particularly a restoring system for restoring a power source for supplying operating energy to the drive means when the power source becomes faulty.
2. Description of the Prior Art
Generally, in a conventional article or good conveyor system, the carriage contains drive means for running the carriage along the predetermined conveying path. With such conveying system, however, installation of drive means increases the size and weight of the carriage.
In stead of providing drive means in the carriage conveyor, a conveyor system has been used in which a propelling force is applied from outside to the carriage. As an example thereof may be mentioned a conveyor system utilizing a linear induction motor. In the conveyor system utilizing the linear induction motor, a reaction plate is provided for the carriage and a plurality of uniformly spaced stators acting as propelling force imparting means are disposed along the conveyance path. When the stators are energized from a power supply source, magnetic flux which varies with time is applied to the reaction plate for causing it to generate a forward propelling force or a reverse propelling force to effect starting and stopping of the carriage.
When the power source becomes abnormal, for example interruption of power supply or fault of the power source, the carriage often stops at an intermediate points between the stators. Such carriage can not be started even when the stators are reenergized, thus requiring a long time to resume the normal state. Consequently the stopped carriage is moved by another carriage when the power source resumes its normal condition or moved by man power to the position of a stator. These methods require time and cost for bringing the carriage to a start position.
According to another prior art technique, the entire conveyance path is inclined with respect to the horizontal or curved in the form of a sine curve or similar curves in the vertical direction for automatically bringing back the carriage by its own weight to the position of the stator as disclosed in Japanese Utility Model Publication No. 34541/1984 (Japanese Utility Model Application No. 105845/1976). With this method, however, it is difficult to design and install the conveyance path. Moreover, the position of the carriage which has stopped during running cannot be determined without relying upon troublesome processings.